Field of the Invention
The present invention relates to a universal connector for cigarette lighter assemblies. More particularly, the present invention is directed to a universal connector that can, for example, be incorporated in a rechargeable flashlight for electrically connecting the rechargeable flashlight to an automotive electrical system via an automobile cigarette lighter receptacle.
2. Description of the Related Art
Connectors, or plugs, have been available for some time which draw electricity from the cigarette lighter receptacle of an automobile. These plugs provide electricity for a wide variety of portable electrical devices, from rechargeable flashlights to laptop computers. However, a number of drawbacks are associated with the plugs presently available. Typically, automobiles in the United States include one of two types of cigarette lighter receptacles. The inventors are aware of no plug presently available which overcomes the structural differences between the two types of receptacles to establish a reliable positive electrical connection via a friction fit with the positive feed portions of both types of receptacles.
In order to be useful for both types of receptacles, most plugs presently in use are maintained within the receptacle by pressure provided by a spring-mounted device against a side wall of the receptacle, with positive electrical contact being provided by simply touching an inner conductor to the positive feed portion of the cigarette lighter receptacle. Given the vibrations that most vehicles experience, such plugs have inherent reliability problems, as contact between conductors can be easily lost. Additionally, such contact is not conducive to drawing large amounts of current through the plug.
One major application for such plugs is rechargeable flashlights. Typically, a plug draws current from the automotive electrical system for recharging a battery associated with the flashlight. For example, U.S. Pat. No. 3,825,740, which issued to Friedman et al. on Jul. 23, 1974, U.S. Pat. No. 4,092,580, which issued to Prinsze on May 30, 1978, and U.S. Pat. No. 4,357,648, which issued to Nelson on Nov. 2, 1982, disclose recharqeable flashlights which draw electricity from cigarette lighter receptacles via plugs of the above-described nature.
In view of the problems associated with plugs, many rechargeable flashlights attempt to avoid the cigarette lighter receptacle as a power source altogether. For example, U.S. Pat. No. 4,092,580 discloses that while a plug for a cigarette lighter assembly can be employed, direct wiring into the automobile electrical system is preferable. The rechargeable flashlight provided in U.S. Pat. No. 4,825,345, issued to Stevens on Apr. 25, 1989, also avoids such plugs by providing means that can be plugged into the fuse box of an automobile.
Many flashlights designed for use in automobiles have additional drawbacks. For example, one problem associated with most rechargeable flashlights is their bulk. Many flashlights designed for automobiles are actually part of flashlight systems, which include the flashlight, a flashlight holder that must be mounted in the automobile, and wires which extend from the holder to the automotive electrical system. The Friedman et al. and Prinsze patents describe such flashlights. Since space is often very limited in modern automobiles, no out of the way place exists for mounting holders, and, more often than not, such flashlights systems are obtrusive.
In this regard, flashlights have been developed which mount directly to cigarette lighter receptacles. For example, see U.S. Pat. Nos. 4,224,658 to Siiberg and 4,713,735 to Hiltman. However, more and more automobiles include cigarette lighter receptacles which are stowed away together with ashtrays within a hinged or sliding compartment or the like. In such cases, these flashlights either do not fit or the compartment must remain at least partially open to allow a flashlight to be inserted. Even in cars with conventionally mounted receptacles, these flashlights tend not to fit discretely or unobtrusively.
A further problem with most rechargeable flashlights is that they lack the ability and flexibility to be useful in emergency situations. For example, most vehicle repairs require two hands, and vehicle problems are typically not in locations that can be illuminated by laying a flashlight on the ground or a flat portion of the vehicle.
In light of these problems, a need exists for a connector which can be used with any of the primary types of cigarette lighter receptacles, is not of questionable reliability due to the vibrations associated with vehicles, and can readily and reliably draw a relatively high current if so needed. A need also exists for a reliable and unobtrusive automobile flashlight which can be readily mounted in useful positions during emergency situations.